SMSC USB2507 Manuel D’Utilisation

Integrated USB 2.0 Compatible 7-Port Hub

Revision 2.3 (08-27-07)

32

SMSC USB2507

The registers shown in 

 are the defined registers in the Hub. Reads to undefined registers

return 00h. Writes to undefined registers have no effect and do not return an error.

Unless otherwise instructed, only a ‘0’ may be written to all reserved registers or bits.

The SMSC Hub can be configured via its internal default configuration. (please see 

 for specific details on how to enable default configuration. 

Please refer to 

 for the internal default values that are loaded when this option is

selected.

The SMSC Hub can be configured via a combination of internal default values and pin strap options.
Please see 

 for specific details on how to enable the

default/pin-strap configuration option. 

The strapping option pins only cover a limited sub-set of the configuration options. The internal default
values will be used for the bits & registers that are not controlled by a strapping option pin. Please
refer to 

 for the internal default values that are loaded when this option is selected. 

The Amber and Green LED pins are sampled after RESET_N negation, and the logic values are used
to configure the hub if the internal default configuration mode is selected. The implementation shown
below (see 

) shows a recommended passive scheme. When a pin is configured with a “Strap

High” configuration, the LED functions with active low signalling, and the PAD will “sink” the current
from the external supply. When a pin is configured with a “Strap Low” configuration, the LED functions
with active high signalling, and the PAD will “source” the current to the external LED. 

7:0

POWER_ON_TIME

Power On Time: The length of time that it takes (in 2 ms intervals) from the 
time the host initiated power-on sequence begins on a port until power is 
good on that port.